code: interfacing a chipcorder isd1760

I am developing a programmer for isd1730, but i have some problems.
Some commands work and some others do not. i.e. PU is working properly,
also SET_PLAY, but SET_REC sometimes is working and some other times isn't.
I am not sure if you can understand what i am trying to say. Weird things happen!
If sb can help....